None.
The present invention relates to a mechanism for use in trimming or cutting roofing materials such as shingles, shakes, or membranes. More specifically, the present invention is drawn to a cutting guide that directs a cutting blade through a given roofing material at a predetermined offset from a given feature of a roof structure.
Heretofore, one of the most time consuming and hence costly procedures in applying roofing materials such as shingles, shakes, tiles, and membranes to roofs has been the hand trimming of the roofing material at or near the valleys, ridges and gable ends of a roof. FIG. 1 illustrates a typical roof valley that is covered with shingles. A valley 14 is the concave juncture of two non-planar roof surfaces. Typically this juncture comprises a seam 18 formed in the sheathing material 16 used to form the roof. For this reason, it is common practice to utilize a water proofing structure known as a valley flashing 20 to prevent water from entering the seam 18 formed at the juncture between the two adjoining roof surfaces. A valley flashing 20 comprises a water impervious material that is preferably a non-corroding metal such as copper or galvanized tin or steel that is nailed in place over the seam 18 between the two adjoining roof surfaces as illustrated in FIG. 1. Preferably a crease or creases are formed along the longitudinal centerline of the valley flashing so that the flashing 20 will conform to the valley 14. The edges of the flashing preferably extend at least six inches from the seam between the adjoining roof surfaces so that the flashing 20 can be nailed in place. Adhesive or sealants may also be used either alone or in conjunction with nails to secure the valley flashing 20 to the valley 14.
As indicated above, the valley flashing 20 may be formed of a longitudinal piece of galvanized tin or steel or of copper and preferably has a simple single crease formed down it is center so that it may conform to the valley. However, currently in the construction trades it is preferred to utilize a valley flashing 20 that is formed in a complex xe2x80x9cWxe2x80x9d shape as illustrated in FIG. 2. This xe2x80x9cWxe2x80x9d shape may be either bent or rolled as the case may be and is usually supplied to a building site in the preformed condition.
In addition, another function of the valley flashing 20 is to act as a channel or sluiceway for water that is falling onto the roof. As can be appreciated, the valley 14 forms a natural channel between the two adjoining roof sections and water and debris flowing down the roof during a rainstorm will naturally flow towards and through the valley 14. Therefore, it is desirable to trim the roofing materials, in the case of FIG. 1 shingles, back from the center of the valley 14 so that relatively smooth valley flashing 20 will form a flow channel having dramatically less flow resistance than would a flow channel formed of a shingle or other roofing materials. In this manner, water and debris may quickly be removed from the roof, thereby avoiding damage to the roof itself.
Unfortunately, given the nature of many roofing materials and especially standard asphalt shingles, the quickest and most flexible manner in which the shingles may be trimmed away from the center of the valley is by hand. Referring again to FIG. 1, a typical pattern for laying roofing materials and particularly shingles over a valley 14 is illustrated. In laying shingles, the installer begins at the lowest edge of a roof and works upward, laying each subsequent course of shingles over an upper edge of the preceding course of shingles. Each course of shingles is manually laid parallel to one another, typically using a chalk line as a guide. When the shingle installer approaches a valley 14, one common practice is to lay the shingles on both sides of the valley 14 completely over the valley 14, being careful not to nail the shingles through the portions of the valley flashing 20 that must remain watertight. After the shingles have been laid over the entire roof the shingle installer will return to the valley 14, snap a chalk line at the predetermined offset distance from the center of the valley flashing 20, and then will proceed to cut the shingles by hand using a utility knife. Alternatively, a roofing installer will first shingle only that portion of the roof that lies to one side of the valley 14. Once the first side of the valley 14 has been shingled, the roofing installer will then trim the installed shingles to the predetermined offset distance. This procedure will then be repeated along the remaining side of the valley 14. While the exact amount of time necessary to trim the shingles away from a valley can vary depending upon whether it is cold and the shingles are hard and stiff, or whether it is warm and the shingles are pliable, it is not uncommon for a twenty-foot section of roof valley to require more than one half hour for a single roofing installer to properly trim. Not only is this work time consuming, but it is also physically demanding and requires a great attention to detail so that the shingles can be trimmed neatly and evenly and so that damage to the flashing can be avoided.
In order to speed the cutting of shingles abutting a roof valley, manufacturers have come up with various types of knives designed for use roofing installers. These designs include knuckle guards, specially hooked blades, and the like. While a number of these improvements do increase the safety and possibly even the efficiency of cutting shingles at a predetermined offset from the valley by hand, the job still requires an inordinate amount of time and is still quite labor intensive.
Another device that is used by shingle installers to cut shingles at a predetermined offset from a valley 14 is a large cutting shear-type device having a base and a cutting arm that is utilized to cut shingles much like a paper cutter cuts paper. Using this device, a roofing installer lays shingles up to and just short of the roof valley and measures and cuts each individual shingle prior to installation to form a uniform shingle offset from the center of the roof valley. As can be appreciated, use of this shingle cutting mechanism is somewhat safer than using a utility knife to cut the shingles after they have been emplaced. However, use of a shear-like cutting device requires the roofing installer to measure and fit each shingle individually along an entire roof valley. Given the large quantity of roof valleys typically present on a roof, the additional measuring and fitting steps may actually increase the amount of time necessary for a roofing installer to install shingles adjacent to a roof valley.
Accordingly, it can easily be seen there is a need for a shingle cutting mechanism that can be used to cut the shingles after they have been laid over a roof valley and which requires no individual measuring and fitting. Preferably such a device will utilize a power saw and will enable the rapid and efficient cutting of the shingles adjacent to a roof valley.
Roof valleys 14 are not the only locations on a building""s roof where the roofing materials must be trimmed. Other locations where the roofing materials must be trimmed include the roof""s ridgeline, the gable end of a roof, and at the ridge of a hip roof. See FIGS. 3, 3a, and 3b. Presently, roofing materials such as shingles that are laid at each of these locations are trimmed using a utility knife as described above for the trimming of roofing materials at the roof valleys. Again, it can easily be seen that there is a need for a mechanism that will allow the neat and efficient trimming of roofing materials at these locations.
Therefore, it is object of the invention to provide a cutting guide for use with a power saw that will allow a roofing installer to automatically cut roofing material such as shingles at a roof valley at a predetermined offset distance. This cutting guide will be required to cleanly cut the roofing materials 12 without damaging the valley flashing 20, the sheathing material 16 of the roof, or the remaining roofing materials themselves. Furthermore, a suitable cutting guide mechanism must be easy to use and faster than the known devices and methodologies for trimming roofing materials at a roof valley
It is another object of the present invention to provide a cutting guide for use with a power saw that can be used to trim roofing materials at the gable end of a roof at a predetermined offset from the fascia boards and drip edge typically used to trim out the gable ends of roofs. Again, such a cutting guide must permit the neat and efficient cutting of the roofing materials avoiding damage to the fascia boards, drip edge, the sheathing of the roof itself, and any damage to the remaining roofing materials.
These and other objectives and advantages of the invention will appear more fully from the following description, made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.
A cutting guide which satisfies the objects of the present invention generally comprises a mounting plate, a post, and a base. The mounting plate of the cutting guide is constructed and arranged to be coupled to a power saw that has a blade for cutting roofing materials. The mounting plate also has an aperture formed therethrough that permit the blade of the power saw to pass through the mounting plate. The post of the cutting guide is secured to and extends from the mounting plate in general alignment with the blade of the power saw. Preferably the post will be sized to follow the blade into a kerf cut into the roofing materials being trimmed. The base of the cutting guide is coupled to the post and has at least one lateral edge that is a positioned at a predetermined distance from the blade in a substantially parallel relation therewith. The predetermined distance between the blade and the lateral edge of the base of the cutting guide is most often the a desired offset distance between a centerline of a roof valley and an offset edge of a roofing material. This predetermined distance is often between two and six inches. In addition, it is contemplated that the base may be made adjustable to accommodate various offset distances.
Preferably, the base is constructed and arranged such that a leading edge thereof is positioned forward of a cutting edge of the blade. In this manner, the leading edge of the base will precede the cutting edge of the blade as the blade cuts the roofing materials. In addition, the base of the will be interposed between the blade and a surface upon which the saw guide is placed without obstructing a forward portion of a cutting edge of the blade. This structure will prevent the blade from cutting a roof surface while the roofing materials are being cut.
Where so desired, an auxiliary shoe may be affixed to the underside of the base. Where this is the case, the shoe will be arranged such that at least one lateral edge thereof is positioned at a predetermined offset distance from the saw blade and in substantially alignment with a cutting direction of the saw blade. It is preferred that a portion of the leading edge of the base or auxiliary shoe that is located away from the center of the roof valley that is being used as a reference surface in trimming the roofing materials be angled rearward to permit the remaining portion of the base adjacent the center of the roof valley to be inserted between the shingles and the roof before the outer portion.
The present invention may be configures as a contiguous apparatus for trimming roofing materials without exceeding the broad scope of the present disclosure. Such a contiguous apparatus for trimming roofing materials may comprise a saw having a motor for turning a saw blade mounted in a chassis. A post is coupled to the chassis of the saw and extending generally downward therefrom in general alignment with the blade of the saw. A base is coupled to the post and has at least one lateral edge positioned a predetermined offset distance from the blade. The at least one lateral edge of the base will be substantially parallel to a cutting direction of the blade. It is envisioned that the angle of the blade with regard to the chassis of the saw be adjustable as will the predetermined distance between the at least one lateral edge of the base and the blade. The base may also comprise an auxiliary shoe coupled to its underside. Such an auxiliary shoe will have at least one lateral edge that is positioned at a predetermined offset distance from the cutting blade in substantially aligned with a cutting direction of the cutting blade.
Another embodiment of the cutting guide comprises a modular structure in which the mounting plate, post, and base may be coupled together or taken apart at need. The mounting plate of this modular embodiment is preferably constructed and arranged to be utilized as a relatively large foot plate for a power saw that is useful in trimming roofing materials at a roof ridge or at the ridge formed by a hip roof.
One optional feature of the present invention comprises a lifter block that has an upwardly beveled leading edge. The lifter block or blocks are positioned at the base of the post so as to deflect an object being cut by the blade away from the post of the cutting guide and hence, away from the blade.
A method of trimming roofing materials to a predetermined offset distance from a roof structure comprising the steps of providing a power saw having a cutting guide for guiding a blade of a power saw coupled thereto that is constructed according the principles of the present invention, inserting the base of the cutting guide between the roof and the roofing materials disposed thereon with the at least one lateral edge abutting the roof structure from which the offset distance is measured and, moving the blade of the power saw along the roof structure while maintaining contact between the at least one lateral edge of the base of the cutting guide and the roof structure from the which the offset distance is measured. This method typically takes advantage of the roof valley to act as a guiding roof structure. Roof valleys almost always have installed thereover a valley flashing against which the lateral edge of the base of the cutting guide may be abutted to set the predetermined offset distance from the center portion of the valley flashing. Alternatively, where roofing materials such as shingles are being trimmed at the gable end of a roof, the cutting guide can be made to abut against the drip edge or fascia of the gable end of the roof to locate the predetermined offset distance.
A method of trimming roofing materials to a predetermined offset distance from a roof structure at the gable end thereof comprises essentially the same steps set forth above. However, in one embodiment of the present invention, the base or shoe of the cutting may be provided with a fin that will abut the drip edge or fascia of the gable end of the roof. In this instance the base of the cutting guide is inserted between the roof and the roofing materials disposed thereon such that the fin that extends from the base of the cutting guide will abuts the roof structure from which the offset distance is measured, i.e. the drip edge or fascia. The blade is then moved along the roof structure while maintaining contact between the fin of the base of the cutting guide and the roof structure from the which the offset distance is measured.
Another embodiment of the cutting guide may be set up to trim roofing materials at the gable end of a roof with little or no modification of the guide. In this embodiment of the cutting guide, the base of the cutting guide is set upon the roofing materials disposed upon the roof with the at least one lateral edge of the base abutting the roof structure from which the offset distance is measured, i.e. the drip edge or fascia of the gable end of the roof. The blade is then moved along the roof structure while maintaining contact between the at least one lateral edge of the base of the cutting guide and the roof structure from the which the offset distance is measured.
Where no roof structure against which the cutting guide may be abutted is present, the cutting guide may be used freehand. In this situation, the roofing installer will identify the location of the offset distance or the location of the trim needed, the base of the cutting guide will be inserted between the roof and the roofing material disposed thereon and, the blade of the power saw will be moved along the roof so as to cut the roofing materials at the location of the identified location.
While the present invention may be used in conjunction with a standard saw blade, it is preferred to utilize a specialized saw blade that designed to cut roofing materials and especially relatively tacky roofing materials such as asphalt shingles without creating a great deal of swarf that can clog a saw. One such blade comprises a hub having a bore for mounting the blade upon a saw arbor formed therethrough wherein the hub has extending radially therefrom a plurality of fingers. Each finger has a projection that extends perpendicular to the plane of the fingers to which are coupled a plurality of spring wires. The spring wires are secured about the projections extending from the fingers to define a cutting edge of the blade. The spring wires are biased so as to spring back after coming into cutting contact with the roofing materials.
Another suitable saw blade comprises a circular saw blade that has a leading edge that is substantially coincident with a radius of the blade. The leading edge of the teeth of the blade comprise a cutting edge that is either beveled or perpendicular to a face of the saw blade.
Yet another suitable saw blade has a tooth profile in which a leading edge of each tooth is angled away from the direction of rotation, with the leading edge being beveled to form sharp cutting edge for slicing a work piece. The cutting edge of the teeth may be a continuous curve or a discontinuous cutting edge having two or more facets.